HIGH-FIELD METAMAGNETIC TRANSITIONS OF NDCO2SI2

High field magnetization of a NdCo2Si2 single crystal has been investi gated up to 15 T below T-N = 32 K. A three-step metamagnetic process w as observed along the c-axis below T-1 = 15 K. Critical fields in the ascending process are H-c1 = 5.0 T, H-c2 = 6.4 T and H-c3 = 13.3 T, an d in the descending process, H-c1 = 2.5 T, H-c2 = 4.5 T and H-c3 = 13. 2 T. The magnetic H-T phase diagram along the c-axis has been determin ed, which can be explained by the self-consistent periodic exchange fi eld model.